Frost dates for Stillwater 1 SE, MN
At Stillwater 1 SE, the median last spring frost (32°F) is Apr 22 and the median first fall frost is Oct 19, for a typical growing season of 178 days. For a 90% chance that the last frost has passed, wait until May 6. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- Apr 22Last spring frost (median)50% chance of 32°F after this date
- May 6Safer planting date10% chance of 32°F after this date
- Oct 19First fall frost (median)50% chance of 32°F by this date
- 178 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 19 | May 2 | May 17 |
| 32°F | Apr 7 | Apr 22 | May 6 |
| 28°F | Mar 31 | Apr 12 | Apr 27 |
| 24°F | Mar 19 | Apr 3 | Apr 18 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 25 | Oct 8 | Oct 23 |
| 32°F | Oct 3 | Oct 19 | Nov 3 |
| 28°F | Oct 15 | Oct 30 | Nov 11 |
| 24°F | Oct 26 | Nov 6 | Nov 19 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 137 days | 158 days | 178 days |
| 32°F | 157 days | 178 days | 200 days |
| 28°F | 180 days | 199 days | 218 days |
| 24°F | 196 days | 215 days | 234 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 55003 | 5a | -20 to -15°F | 4 km |
| 54082 | 4b | -25 to -20°F | 5 km |
| 54016 | 4b | -25 to -20°F | 11 km |
| 55043 | 5a | -20 to -15°F | 11 km |
| 54025 | 4b | -25 to -20°F | 15 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00218037, at 45.0417, -92.7975, elevation 216 m (710 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 147.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Stillwater 2sw (4 km)
- St. Paul (21 km)
- Vadnais Lake (23 km)
- St. Paul Downtown Airport (24 km)
- U Of Mn St. Paul (31 km)
- St. Paul 3sw (31 km)
- Hastings Dam 2 (32 km)
- Forest Lake 5ne (33 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.